1. Field of Invention
The present invention relates to transportation of cargo and, more particularly, to a telescopic supportive apparatus for supporting and therefore positioning cargo in a truck.
2. Related Prior Art
Cargo is transported to buyers from sellers through various vehicles such as airplanes, ships, trains, and trucks. Trucks are the most often used vehicles among them. Cargo is located in a container of a truck. Various items of the cargo are stacked. The items however rattle inevitably during the transportation. Some of the items on the top might fall from the others on the bottom and get damaged.
To support and position cargo in a container, the present inventor has devised telescopic supportive apparatuses claimed in Taiwanese Patent Publication Nos. 241668 and 371434. Such a telescopic supportive apparatus includes an internal tube, an external tube, a mount, a toothed or ratcheted wheel, a handle and two spring-biased detents. The internal tube is telescopically inserted in the external tube. The mount is secured to the external tube. The toothed or ratcheted wheel and the handle are located on the mount. The first spring-biased detent is movably located on the mount while the second spring-biased detent is movably located on the handle. In use, the handle is pivoted in a direction, and the first spring-biased detent rattles and moves on the toothed or ratcheted wheel while the second spring-biased detent engages with the toothed or ratcheted wheel. Thus, the second spring-biased detent spins the toothed or ratcheted wheel which extends the internal tube from the external tube. Then, the handle is pivoted in an opposite direction, and the first spring-biased detent engages with and stops the toothed or ratcheted wheel while the second spring-biased detent rattles and moves on the toothed or ratcheted wheel. The toothed or ratcheted wheel positions the internal tube relative to the external tube. By pivoting the handle to and fro, the internal tube is extended from the external tube little by little. Both the spring-biased detents can be disengaged from the toothed or ratcheted wheel to allow free insertion of the internal tube into the external tube.
The telescopic supportive apparatuses can be used as a crossbar or a post. When it is used as a post, the internal tube might drop into the external tube rapidly because of the gravity. The rapidly dropping internal tube might hurt a user.
The present invention is therefore intended to obviate or at least alleviate the problems encountered in prior art.